Apparatus, method, and medium controlling electrical stimulation and/or health training/monitoring

ABSTRACT

An apparatus, method, and medium for generating electrical stimulation, including an electromyogram detector detecting an electromyographic signal of a body, a fatigue index calculator calculating a fatigue index indicating a degree of muscle fatigue by converting the electromyographic signal detected by the electromyogram detector during a predetermined time unit into a frequency-domain electromyographic signal, and an electrical stimulation signal generator adjusting an electrical stimulation signal according to the calculated fatigue index and generating the electrical stimulation signal. Accordingly, a health training/monitoring apparatus can include an electrical stimulation generator adjusting an electrical stimulation signal according to a degree of fatigue and generating the electrical stimulation signal, a physical activity monitor monitoring a physical activity using at least one of a heart rate measurer and an accelerometer, and a mode selector selectively driving the electrical stimulation generator or the physical activity monitor according to an amount of the physical activity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Korean PatentApplication No. 10-2004-0042507, filed on Jun. 10, 2004, in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a medical aid, and more particularly,to an apparatus, method, and medium controlling electrical stimulationusing an electromyographic signal and/or health training/monitoring withthe same.

2. Description of the Related Art

Conventional devices for electrically stimulating abdominal muscles tostrengthen the abdominal muscles cannot quantitatively monitor the stateof the abdominal muscles after abdominal muscle-strengthening exercise.Therefore, the conventional devices cannot display a correspondingelectrical stimulation level, according to the state of abdominalmuscles of each individual. Further, repeated abdominalmuscle-strengthening exercise may aggravate fatigued abdominal muscles,with excessive exercise actually hindering the restoration of abdominalmuscles and produce adverse effects.

In addition, since conventional heart monitors are worn around thechest, e.g., to measure heart rates, they can cause a sense of pressureupon the chest. In addition, conventionally, there have not been anyapparatuses, methods, or media managing patients having difficulty withmovement by monitoring their back muscles and walking patterns, in realtime, nor have there been any apparatuses, methods, or media formeasuring heart rates and stimulating abdominal muscles simultaneously.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide apparatuses, methods, andmedia controlling electrical stimulation to a degree that the electricalstimulation does not aggravate fatigued muscles by calculating a degreeof muscle fatigue by measuring a level of electromyogram (EMG) beforeand after muscle exercises.

Embodiments of the present invention also provides healthtraining/monitoring apparatuses, methods, and media with such electricalstimulation, in which electrical stimulation may be controlled based onmuscle fatigue, the degree of muscle fatigue can be monitored,information regarding physical activity and walking patterns can bemonitored by measuring a heart rate and acceleration, while a user isperforming aerobic exercises, such as running, jogging, walking, orstepping, and calories expended may be calculated.

To achieve the above and/or other aspects and advantages, embodiments ofthe present invention set forth an electrical stimulation apparatususing an electromyographic measurement, including an electromyogramdetector detecting an electromyographic signal from a body, a fatigueindex calculator calculating a fatigue index indicating a degree ofmuscle fatigue, for at least a muscle of the body, by converting thedetected electromyographic signal, detected during a predetermined timeunit, into a frequency-domain electromyographic signal, and anelectrical stimulation signal generator adjusting an electricalstimulation signal, for application to the body, based on the calculatedfatigue index and generating the electrical stimulation signal. Here,the electromyogram detector may include an electromyogram detectionelectrode.

The fatigue index calculator may include an initial median frequencyoutput unit to measure an electromyogram at an initial point, of thepredetermined time unit, to convert the measured initial pointelectromyogram into an initial frequency-domain electromyogram, and tooutput an initial median frequency, a final median frequency output unitto measure an electromyogram at a final point, of the predetermined timeunit, to convert the measured final point electromyogram into a finalfrequency-domain electromyogram, and to output a final median frequency,and a fatigue index output unit to determine the fatigue index based ona ratio of the initial median frequency to a difference between theinitial median frequency and the final median frequency.

The electrical stimulation signal generator may adjust the electricalstimulation signal by changing a size, a cycle, and/or a pattern of theelectrical stimulation signal.

To achieve the above and/or other aspects and advantages, embodiments ofthe present invention set forth a method of generating electricalstimulation using an electromyographic signal, including detecting anelectromyographic signal from a body using a predetermined medium fordetecting an electromyogram, calculating a fatigue index indicating adegree of muscle fatigue, for a muscle of the body, by converting thedetected electromyographic signal, detected during a predetermined timeunit, into a frequency-domain electromyographic signal, and adjusting anelectrical stimulation signal according to the calculated fatigue indexand generating the adjusted electrical stimulation signal.

The calculating of the fatigue index may include measuring an initialelectromyogram signal at an initial point, of the predetermined timeunit, converting the measured initial point electromyogram signal intoan initial frequency-domain electromyogram signal, and outputting aninitial median frequency, measuring a final electromyogram signal at afinal point, of the predetermined time unit, converting the measuredfinal point electromyogram signal into a final frequency-domainelectromyogram signal, and outputting a final median frequency, anddetermining the fatigue index based on a ratio of the initial medianfrequency to a difference between the initial median frequency and thefinal median frequency.

In the adjusting and generating of the electrical stimulation signal,the electrical stimulation signal may be adjusted by changing a size, acycle, and/or a pattern of the electrical stimulation signal.

To achieve the above and/or other aspects and advantages, embodiments ofthe present invention set forth a health training/monitoring apparatus,including an electrical stimulation generator to adjust an electricalstimulation signal based on a degree of fatigue, of a muscle of a body,and generating the adjusted electrical stimulation signal, a physicalactivity monitor to monitor a physical activity of a user using at leastone of a heart rate measurer and an accelerometer for the body, and amode selector selectively driving the electrical stimulation generatoror the physical activity monitor based on an amount of the monitoredphysical activity.

Here, the electrical stimulation generator may include an electromyogramdetector to detect an electromyographic signal of the body, a fatigueindex calculator to calculate a fatigue index indicating the degree offatigue by converting the detected electromyographic signal, detectedduring a predetermined time unit, into a frequency-domainelectromyographic signal, and an electrical stimulation signal generatorto adjust the electrical stimulation signal based on the calculatedfatigue index and to generate the adjusted electrical stimulationsignal.

The physical activity monitor may include the heart rate measurer tomeasure a heart rate using a predetermined electrode attached to thebody, the accelerometer to measure an acceleration of physical movementof the body; and an activity output unit to output at least one of aphysical activity pattern and calories expended based on the measuredheart rate and/or the measured acceleration. In addition, theaccelerometer may measure the acceleration of the physical movement inany one of a one-axis direction, two-axis direction, or three-axisdirection.

Further, the mode selector may drive the physical activity monitor whenan output waveform of the accelerometer is greater than a predeterminedthreshold value and drives the electrical stimulation generator when theoutput waveform of the accelerometer is not greater than thepredetermined threshold value.

The apparatus may also be a waist belt or a patch. The waist belt or thepatch may include a first layer including a plurality of electrodes formeasuring the heart rate, a plurality of electrodes for the electricalstimulation, and a plurality of electrodes for the measuring of theelectromyographic signal, and a second layer including the accelerometermeasuring the acceleration of the physical movement and a predeterminedcontroller. An airbag layer inflatable and deflatable by air may also beinterposed between the first layer and the second layer.

To achieve the above and/or other aspects and advantages, embodiments ofthe present invention set forth a health training/monitoring method,including determining whether a physical activity is dynamic or static,monitoring the physical activity using at least one of a heart ratemeasurer and an accelerometer when the physical activity is dynamic, andadjusting an electrical stimulation signal based on a degree of musclefatigue, of at least a muscle of a body, and generating the adjustedelectrical stimulation signal when the physical activity is static.

In the determining of whether the physical activity is dynamic orstatic, the physical activity may be determined to be dynamic when avalue of the physical activity is greater than a predetermined thresholdvalue for a predetermined period of time, and the physical activity maybe determined as static when a value of the physical activity is notgreater than the predetermined threshold value for the predeterminedperiod of time.

Further, the monitoring of the physical activity may include measuringthe heart rate using a predetermined electrode attached to the body whenthe physical activity is dynamic, measuring acceleration of physicalmovement of the body using an accelerometer, and outputting at least oneof a physical activity pattern and calories expended using the measuredheart rate and the measured acceleration. In addition, the adjusting andgenerating of the electrical stimulation signal may include detecting anelectromyographic signal of the body, calculating a fatigue indexindicating the degree of muscle fatigue by converting the detectedelectromyographic signal, detected during a predetermined time unit,into a frequency-domain electromyographic signal, and adjusting theelectrical stimulation signal based on the calculated fatigue index andgenerating the adjusted electrical stimulation signal.

To achieve the above and/or other aspects and advantages, embodiments ofthe present invention set forth an electrical stimulation apparatus,including an electromyogram detector detecting electromyographic signalsfrom a body, a fatigue index calculator calculating a fatigue indexindicating a degree of muscle fatigue, for at least a muscle in a body,by converting at least two detected electromyographic signals intorespective frequency-domain electromyographic signals, with thecalculated fatigue index being based on a ratio with the at least twofrequency-domain electromyographic signals, and an electricalstimulation signal generator generating an electrical stimulationsignal, for application to the body, based on the calculated fatigueindex.

The apparatus may further include a heart rate measurer to measure aheart rate using a predetermined electrode attached to the body, and anactivity output unit to output at least one of a physical activitypattern and calories expended based on the measured heart rate. Further,the apparatus may include an accelerometer to measure an acceleration ofphysical movement of the body, and an activity output unit to output atleast one of a physical activity pattern and calories expended based onthe measured acceleration. Here, when the measured acceleration isgreater than a predetermined threshold value the electrical stimulationsignal generator may not generate the electrical stimulation signal.

The at least two detected electromyographic signals may be detected atleast at an initial point in a predetermined period and a final point inthe predetermined period, respectively. The initial point may occur whenthe electrical stimulation apparatus is applied to operate on the body,and the final point may occur when the electrical stimulation apparatusis removed from operating on the body.

To achieve the above and/or other aspects and advantages, embodiments ofthe present invention set forth media including computer readable codeimplementing embodiments of the present invention.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be apparentfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 illustrates a block diagram of an apparatus controllingelectrical stimulation using an electromyographic signal, according toan embodiment of the present invention;

FIG. 2 illustrates a belt including an electromyogram (EMG) detectionelectrode to monitor a degree of abdominal/back muscle fatigue based ona biological signal, and an amplifier amplifying a detected signal,according to an embodiment of the present invention;

FIG. 3 illustrates a detailed block diagram of a fatigue indexcalculator, e.g., such as that illustrated in FIG. 1;

FIG. 4 illustrates a flowchart for a method for generating an electricalstimulation signal, according to an embodiment of the present invention;

FIG. 5 illustrates a flowchart for a method for calculating a fatigueindex, e.g., such as in operation 420 of FIG. 4;

FIG. 6 illustrates a block diagram of a health training/monitoringapparatus, according to an embodiment of the present invention;

FIG. 7 illustrates a detailed block diagram of a physical activitymonitor, such as that illustrated in FIG. 6, according to an embodimentof the present invention;

FIG. 8 is a sectional view of a waist belt or a patch, according to anembodiment of the present invention;

FIG. 9 illustrates a belt including an EMG detection electrode and anelectrode for detecting a heart rate of abdominal muscles and to monitora degree of abdominal/back fatigue using a biological signal, and anamplifier amplifying the detected signal, according to an embodiment ofthe present invention;

FIG. 10 illustrates a belt including a biological signal detectionelectrode to monitor an activity using an acceleration signal, accordingto an embodiment of the present invention;

FIG. 11A illustrates an abdomen EMG when electrodes are attached to theupper and lower abdomen, according to an embodiment of the presentinvention;

FIG. 11B illustrates an abdomen EMG when electrodes are attached to theright and left sides of the abdomen, according to an embodiment of thepresent invention;

FIG. 12 illustrates a schematic configuration of the healthtraining/monitoring apparatus detecting a signal for monitoring thedegree of abdominal/back fatigue and a heart rate using a biologicalsignal, when a physical activity is in a static mode, according to anembodiment of the present invention;

FIG. 13 illustrates a schematic configuration of the healthtraining/monitoring apparatus detecting a signal for monitoring aphysical activity, using an acceleration signal, to estimate caloriesexpended and monitor a walking pattern, when the physical activity is ina dynamic mode, according to an embodiment of the present invention;

FIG. 14 illustrates a schematic configuration of a healthtraining/monitoring apparatus detecting a signal for monitoring a degreeof abdominal fatigue, a heart rate, and a walking pattern by monitoringan EMG, the heart rate, and an activity of a patient having difficultywith movement or a patient with back pain, according to an embodiment ofthe present invention;

FIG. 15 illustrates a flowchart illustrating a method of generating anelectrical stimulation signal, according to an embodiment of the presentinvention;

FIG. 16 illustrates a flowchart for monitoring a physical activity, suchas operation 1560 of FIG. 15, according to an embodiment of the presentinvention;

FIG. 17 illustrates a waveform diagram of a heart rate measured byelectrodes attached to the upper and lower abdomen when a belt is wornaround the waist, according to an embodiment of the present invention;

FIG. 18 illustrates a waveform diagram of a heart rate measured byelectrodes attached to the right and left sides of the abdomen when thebelt is worn around the waist, according to an embodiment of the presentinvention;

FIG. 19 illustrates a waveform diagram of a heart rate measured byelectrodes attached to the right and left parts of the left side of theabdomen when the belt is worn around the waist, according to anembodiment of the present invention;

FIG. 20 illustrates a waveform diagram of a heart rate measured byelectrodes attached to the right and left sides of the abdomen when thebelt is worn around the waist, according to an embodiment of the presentinvention; and

FIG. 21 illustrates a waveform diagram of a heart rate measured byelectrodes attached to the right and left parts of the right side of theabdomen when the belt is worn around the waist, according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below to explain the presentinvention by referring to the figures.

FIG. 1 illustrates a block diagram of an apparatus for controllingelectrical stimulation using an electromyographic signal, according toan embodiment of the present invention. The apparatus can include anelectromyogram (EMG) detector 100, a fatigue index calculator 120, andan electrical stimulation signal generator 140.

The EMG detector 100 detects an electromyographic signal of the body,and can be detected using an EMG detection electrode, for example. TheEMG detection electrode is attached to the abdomen to monitor a degreeof abdominal muscle fatigue, before and after exercise. In addition, theEMG detection electrode can be attached to the back, along the waist, tomonitor a degree of back muscle fatigue for those with back pain, forexample.

FIG. 2 illustrates a belt including an EMG detection electrode tomonitor the degree of abdominal/back muscle fatigue, based on abiological signal, and an amplifier amplifying a detected signal.

The fatigue index calculator 120 can calculate a fatigue indexindicating the degree of muscle fatigue by converting anelectromyographic signal detected by the EMG detector 100, during apredetermined time unit, into a frequency-domain signal.

FIG. 3 illustrates a detailed block diagram of a fatigue indexcalculator 120, with the fatigue index calculator 120 including aninitial median frequency output unit 300, a final median frequencyoutput unit 320, and a fatigue index output unit 340. The initial medianfrequency output unit 300 measures an EMG at an initial point, of apredetermined time unit, converts the EMG into a frequency-domain EMG,and outputs a median frequency (initial median frequency). The finalmedian frequency output unit 320 measures an EMG at a final point of thepredetermined time unit, converts the EMG into a frequency-domain EMG,and outputs another median frequency (final median frequency). Thefatigue index output unit 340 determines a fatigue index as a ratio ofthe initial median frequency to a difference between the initial medianfrequency and the final median frequency.

The electrical stimulation signal generator 140 can generate anelectrical stimulation signal according to the fatigue index. Theelectrical stimulation signal generator 140 can adjust a size, a cycle,and/or a pattern of an electrical stimulation signal, for example.

FIG. 4 illustrates a flowchart for generating an electrical stimulationsignal, according to an embodiment of the present invention.

An electromyographic signal of the body can be detected using anelectromyographic signal detection electrode attached to a predeterminedEMG detection medium, such as the belt illustrated in FIG. 2 (operation400). The electromyographic signal detected, during a predetermined timeunit, can be converted into a frequency-domain electromyographic signaland a fatigue index, indicating the degree of muscle fatigue, can becalculated using the frequency-domain electromyographic signal(operation 420).

Here, the predetermined time unit can be a time unit for measuring amedian frequency and may be set arbitrarily. For example, the momentwhen the belt to which the EMG detection electrode is attached is wornmay be set as a starting point and the moment when the belt is taken offmay be set as a final point Alternatively, a period between the startingand the final points may be divided into several sections, and startingand final points of each section may be set as the time unit formeasuring the median frequency.

FIG. 5 illustrates a flowchart for calculating the fatigue index inoperation 420, for example, in greater detail. Referring to FIG. 5,after the belt is worn, an EMG signal at the initial point of thepredetermined time unit for measuring the median frequency may bemeasured and the EMG signal is converted into a frequency-domain signal.As a result, an initial median frequency f_(mi) can then be output(operation 500).

After carrying out daily activities or exercising, the EMG signal at thefinal point of the predetermined time can be measured and the EMG signalconverted into a frequency-domain signal. As a result, a final medianfrequency f_(mf) can be output (operation 520).

Once the initial median frequency f_(mi) and the final median frequencyf_(mf) are obtained, the fatigue index may be calculated as a ratio ofthe initial median frequency f_(mi) to a difference between the initialmedian frequency f_(mi) and the final median frequency f_(mf) (operation540). If the fatigue index is obtained using an EMG electrode attachedto abdominal muscles the degree of abdominal fatigue can be monitored.If the fatigue index is obtained using an EMG electrode attached to backmuscles the degree of back muscle fatigue can be monitored.$\begin{matrix}{{{Fatigue}\quad{Index}\quad(\%)} = {\frac{f_{m\quad i} - f_{mf}}{f_{m\quad i}} \times 100}} & {{Equation}\quad(1)}\end{matrix}$

Once the fatigue index is calculated, in operation 420, an electricalstimulation signal corresponding to the fatigue index can be generatedso as to not increase muscle fatigue (operation 440). The electricalstimulation signal can be adjusted by changing its size, cycle, and/orpattern, for example.

A health training/monitoring apparatus, method, and medium, according toan embodiment of the present invention will now be described.

FIG. 6 illustrates a block diagram of the health training/monitoringapparatus, according to an embodiment of the present invention. Thehealth training/monitoring apparatus can include an electricalstimulation generator 620, a physical activity monitor 640, and a modeselector 600.

The electrical stimulation generator 620 generates an electricalstimulation signal, adjusted according to the degree of muscle fatigue.A detailed description of the electrical stimulation generator 620 willbe omitted here since it can be similar to the aforementioned apparatusgenerating electrical stimulation of FIG. 1.

The physical activity monitor 640 can monitor physical activity, usingat least one of a heart rate measurer and an accelerometer. FIG. 7 is adetailed block diagram of the physical activity monitor 640. Asillustrated, the physical activity monitor 640 can include a heart ratemeasurer 700, an accelerometer 720, and an activity output unit 740.

The heart rate measurer 700 measures a heart rate using a predeterminedelectrode attached to the body, for example. The accelerometer 720measures acceleration of physical movement. The accelerometer 720 canmeasure the acceleration of physical movement in any one of one-axisdirection, two-axis direction, or three-axis direction, for example. Theone-axis direction denotes one direction in which the body moves, suchas the direction in front of the body. The two-axis direction denotestwo directions in which the body moves, such as front and right & left,for example. The three-axis direction denotes three directions such asfront & rear, right & left, and top & bottom, for example.

The activity output unit 740 can output at least one of a physicalactivity pattern and calories expended (i.e., consumed by an activity)using the heart rate measured by the heart rate measurer 700 and theacceleration measured by the accelerometer 720. The activity output unit740 includes an exercise quantity calculator 742 and an activity patternoutput unit 744. The exercise quantity calculator 742 can calculate anamount of exercise using a heart rate and acceleration, with theactivity pattern output unit 744 determining the corresponding activitypattern, such as walking, running, or ascending/descending stairs, usingthe heart rate and acceleration.

If an acceleration sensor (acceleration electrode) is attached to eachof the front and rear of a belt worn around the waist, the walkingpattern of a user can be monitored using the acceleration detected bythe acceleration sensor (acceleration electrode). If an EMG sensor (EMGelectrode) is also placed around the waist, along the back, the degreeof back muscle fatigue can be monitored using an electromyographicsignal detected by the EMG sensor (EMG electrode). In this regard,activity information of patients having difficulty with movement can bemonitored all the time using their walking patterns and the varyingdegrees of muscle fatigue, thereby producing information useful forrehabilitative training, for example.

The mode selector 600, illustrated in FIG. 6, selectively drives theelectrical stimulation generator 620 and the physical activity monitor640 depending on the degree of physical activity. The degree of thephysical activity may be determined based on an output waveform of theaccelerometer 720 being greater than a predetermined threshold for apredetermined period of time. For example, when a value of the outputwaveform of the accelerometer 720 is greater than a predeterminedthreshold value for a predetermined period of time, the mode of thephysical activity can be designated a dynamic mode. Conversely, when thevalue of the output waveform of the accelerometer 720 is not greaterthan the predetermined threshold value for the predetermined period oftime, the mode of the physical activity can be designated a static mode.The mode may also be selected manually by a user, for example.

A health training/monitoring apparatus using electrical stimulation maytake the form of a belt worn around the waist or a patch worn around thearm, for example. FIG. 8 is a sectional view of such a waist belt orpatch. The waist belt or the patch can include a first layer 80 and asecond layer 85, for example. The first layer 80 may include a pluralityof electrodes 800 and 810 for measuring a heart rate, a plurality ofelectrodes 820 and 830 for electrical stimulation, and a plurality ofelectrodes 800 and 810 for measuring electromyographic signals. Thesecond layer 85 can include an accelerometer 840 measuring accelerationand a predetermined controller 850.

In addition, the belt or patch may include an airbag layer 83,inflatable or deflatable by air, which may be interposed between thefirst layer 80 and the second layer 85. When the belt or the patch isworn around the waist or the arm, the airbag layer 83 can keep the beltor the patch close to the waist or the arm to prevent it from moving tothe right/left or sliding up/down during physical activities, e.g., suchduring exercising.

FIG. 9 illustrates a belt including an EMG detection electrode, and anelectrode for detecting a heart rate, for abdominal muscles to monitorthe degree of abdominal/back fatigue using a biological signal, and anamplifier amplifying a corresponding detected signal. FIG. 10illustrates a belt including a biological signal detection electrode formonitoring activity using an acceleration signal. FIG. 11A illustratesan abdomen EMG when electrodes are attached to the upper and lowerabdomen, according to an embodiment of the present invention, and FIG.11B illustrates an abdomen EMG when electrodes are attached to the rightand left sides of the abdomen, according to an embodiment of the presentinvention.

FIG. 12 illustrates a schematic configuration of a healthtraining/monitoring apparatus detecting a signal monitoring a degree ofabdominal/back fatigue, and a heart rate, using a biological signal whena physical activity is in the aforementioned static mode, according toan embodiment of the present invention. FIG. 13 illustrates a schematicconfiguration of a health training/monitoring apparatus detecting asignal monitoring physical activity using an acceleration signal toestimate calories expended and to monitor a walking pattern when thephysical activity is in the aforementioned dynamic mode, according to anembodiment of the present invention.

FIG. 14 illustrates a schematic configuration of a healthtraining/monitoring apparatus monitoring a degree of abdominal fatigue,a heart rate, and a walking pattern by monitoring an EMG, the heartrate, and an activity of a patient having difficulty with movement or apatient with back pain, according to an embodiment of the presentinvention. FIG. 15 illustrates a flowchart for generating an electricalstimulation signal, according to an embodiment of the present invention.The operation of the health training/monitoring apparatus will now bedescribed with reference to FIG. 15.

During daily activities (operation 1500), when a belt or a patch is wornaround the body, the mode selector 600 determines whether a physicalactivity is in a dynamic or static mode (operation 1520). When thephysical activity is greater than a predetermined threshold value, for apredetermined period of time, the mode selector 600 designates the modeof the physical activity as being dynamic. Otherwise, the mode selector600 designates the mode of the physical activity as being static.

When the physical activity is in the static mode, the electricalstimulation generator 620 can adjust and generate an electricalstimulation signal according to a detected degree of muscle fatigue(operation 1540). The degree of fatigue can be determined by a fatigueindex, e.g., as calculated by the above Equation 1, with a method ofadjusting the electrical stimulation signal being similar to the abovementioned method of generating an electrical stimulation signal,discussed with relation to FIG. 4.

When the physical activity is in the dynamic mode, the physical activitymonitor 640 can monitor the physical activity using at least one of theheart rate measurer 700 and the accelerometer 720 (operation 1560), forexample.

FIG. 16 illustrates a flowchart for monitoring the physical activity, ofoperation 1560, in greater detail. When the physical activity isdesignated as corresponding to the dynamic mode, the heart rate can bemeasured using a predetermined electrode attached to the body, andacceleration of physical movement can be measured using theaccelerometer 720 (operation 1600). At least one of a physical activitypattern and calories expended can be determined based on informationregarding the measured heart rate and acceleration (operation 1650).

FIGS. 17 through 21 illustrate waveform diagrams of a heart ratemeasured by electrodes attached to the abdomen, according to anembodiment of the present invention. FIG. 17 illustrates a waveformdiagram of a heart rate measured by electrodes attached to the upper andlower abdomen when a belt is worn around the waist. FIG. 18 illustratesa waveform diagram of a heart rate measured by electrodes attached tothe right and left sides of the abdomen or the right and left parts ofthe right or left side of the abdomen when the belt is worn around thewaist.

FIG. 19 illustrates a waveform diagram of a heart rate measured byelectrodes attached to the right and left parts of the left side of theabdomen when the belt is worn around the waist, FIG. 20 illustrates awaveform diagram of a heart rate measured by electrodes attached to theright and left sides of the abdomen when the belt is worn around thewaist, and FIG. 21 illustrates a waveform diagram of a heart ratemeasured by electrodes attached to the right and left parts of the rightside of the abdomen when the belt is worn around the waist.

Embodiments of the present invention can be implemented by a computer(s)(including all the devices capable of processing information) throughcomputer readable code on a medium, e.g., a computer-readable recordingmedium. The medium may include all kinds of recording devices where datareadable by a computer system can be stored/transferred. Media mayinclude ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, or opticaldata storages, or the Internet, for example.

Embodiments of the present invention provide an index for quantitativelymonitoring progress based on a degree of abdominal fatigue by measuringthe degree of abdominal fatigue before and after repeated abdominalmuscle exercise. Therefore, electrical stimulation may be applied to theabdomen such that the abdominal muscle exercise does not aggravate thefatigued abdominal muscle. The user may also control the degree of theelectrical stimulation.

When a user is performing aerobic exercises such as running, jogging,walking, or stepping, while wearing an abdominal belt including a heartrate measuring sensor at the abdomen and an acceleration measuringsensor at the abdomen and back, the heart rate and acceleration of theuser can be measured simultaneously. Accordingly, it is possible toestimate information such as calories expended, thereby enablingquantitative exercise by suggesting an intensity of exercise, for alevel of calories expended, for healthy people or patients havingdifficulty with movement.

Further, a walking pattern of a user can be monitored using theacceleration sensors attached to the front and rear of the belt wornaround the waist, and the degree of muscle fatigue can be monitoredusing an EMG sensor placed around the waist, along the back, forexample. In this regard, activity information for patients havingdifficulty with movement can be monitored, thereby producing informationuseful for rehabilitative training.

In particular, it is possible to monitor the status of lumbar protectionand activity of patients with lumbar troubles and to provide feedbackinformation according to walking patterns of patients, for example,having difficulty with movement, thereby inducing effectiverehabilitative training.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. An electrical stimulation apparatus using an electromyographicmeasurement, comprising: an electromyogram detector detecting anelectromyographic signal from a body; a fatigue index calculatorcalculating a fatigue index indicating a degree of muscle fatigue, forat least a muscle of the body, by converting the detectedelectromyographic signal, detected during a predetermined time unit,into a frequency-domain electromyographic signal; and an electricalstimulation signal generator adjusting an electrical stimulation signal,for application to the body, based on the calculated fatigue index andgenerating the electrical stimulation signal.
 2. The apparatus of claim1, wherein the electromyogram detector comprises an electromyogramdetection electrode.
 3. The apparatus of claim 1, wherein the fatigueindex calculator comprises: an initial median frequency output unit tomeasure an electromyogram at an initial point, of the predetermined timeunit, to convert the measured initial point electromyogram into aninitial frequency-domain electromyogram, and to output an initial medianfrequency; a final median frequency output unit to measure anelectromyogram at a final point, of the predetermined time unit, toconvert the measured final point electromyogram into a finalfrequency-domain electromyogram, and to output a final median frequency;and a fatigue index output unit to determine the fatigue index based ona ratio of the initial median frequency to a difference between theinitial median frequency and the final median frequency.
 4. Theapparatus of claim 1, wherein the electrical stimulation signalgenerator adjusts the electrical stimulation signal by changing a size,a cycle, and/or a pattern of the electrical stimulation signal.
 5. Amethod of generating electrical stimulation using an electromyographicsignal, comprising: detecting an electromyographic signal from a bodyusing a predetermined medium for detecting an electromyogram;calculating a fatigue index indicating a degree of muscle fatigue, for amuscle of the body, by converting the detected electromyographic signal,detected during a predetermined time unit, into a frequency-domainelectromyographic signal; and adjusting an electrical stimulation signalaccording to the calculated fatigue index and generating the adjustedelectrical stimulation signal.
 6. The method of claim 5, wherein thecalculating of the fatigue index comprises: measuring an initialelectromyogram signal at an initial point, of the predetermined timeunit, converting the measured initial point electromyogram signal intoan initial frequency-domain electromyogram signal, and outputting aninitial median frequency; measuring a final electromyogram signal at afinal point, of the predetermined time unit, converting the measuredfinal point electromyogram signal into a final frequency-domainelectromyogram signal, and outputting a final median frequency; anddetermining the fatigue index based on a ratio of the initial medianfrequency to a difference between the initial median frequency and thefinal median frequency.
 7. The method of claim 5, wherein, in theadjusting and generating of the electrical stimulation signal, theelectrical stimulation signal is adjusted by changing a size, a cycle,and/or a pattern of the electrical stimulation signal.
 8. A healthtraining/monitoring apparatus, comprising: an electrical stimulationgenerator to adjust an electrical stimulation signal based on a degreeof fatigue, of a muscle of a body, and generating the adjustedelectrical stimulation signal; a physical activity monitor to monitor aphysical activity of a user using at least one of a heart rate measurerand an accelerometer for the body; and a mode selector selectivelydriving the electrical stimulation generator or the physical activitymonitor based on an amount of the monitored physical activity.
 9. Thehealth training/monitoring apparatus of claim 8, wherein the electricalstimulation generator comprises: an electromyogram detector to detect anelectromyographic signal of the body; a fatigue index calculator tocalculate a fatigue index indicating the degree of fatigue by convertingthe detected electromyographic signal, detected during a predeterminedtime unit, into a frequency-domain electromyographic signal; and anelectrical stimulation signal generator to adjust the electricalstimulation signal based on the calculated fatigue index and to generatethe adjusted electrical stimulation signal.
 10. The healthtraining/monitoring apparatus of claim 8, wherein the physical activitymonitor comprises: the heart rate measurer to measure a heart rate usinga predetermined electrode attached to the body; the accelerometer tomeasure an acceleration of physical movement of the body; and anactivity output unit to output at least one of a physical activitypattern and calories expended based on the measured heart rate and/orthe measured acceleration
 11. The health training/monitoring apparatusof claim 10, wherein the accelerometer measures the acceleration of thephysical movement in any one of a one-axis direction, two-axisdirection, or three-axis direction.
 12. The health training/monitoringapparatus of claim 8, wherein the mode selector drives the physicalactivity monitor when an output waveform of the accelerometer is greaterthan a predetermined threshold value and drives the electricalstimulation generator when the output waveform of the accelerometer isnot greater than the predetermined threshold value.
 13. The healthtraining/monitoring apparatus of claim 8, wherein the apparatus is awaist belt or a patch.
 14. The health training/monitoring apparatus ofclaim 13, wherein the waist belt or the patch comprises: a first layercomprising a plurality of electrodes for measuring the heart rate, aplurality of electrodes for the electrical stimulation, and a pluralityof electrodes for the measuring of the electromyographic signal; and asecond layer comprising the accelerometer measuring the acceleration ofthe physical movement and a predetermined controller.
 15. The healthtraining/monitoring apparatus of claim 14, wherein an airbag layerinflatable and deflatable by air is interposed between the first layerand the second layer.
 16. A health training/monitoring method,comprising: determining whether a physical activity is dynamic orstatic; monitoring the physical activity using at least one of a heartrate measurer and an accelerometer when the physical activity isdynamic; and adjusting an electrical stimulation signal based on adegree of muscle fatigue, of at least a muscle of a body, and generatingthe adjusted electrical stimulation signal when the physical activity isstatic.
 17. The method of claim 16, wherein in the determining ofwhether the physical activity is dynamic or static, the physicalactivity is determined to be dynamic when a value of the physicalactivity is greater than a predetermined threshold value for apredetermined period of time, and the physical activity is determined asstatic when a value of the physical activity is not greater than thepredetermined threshold value for the predetermined period of time. 18.The method of claim 16, wherein the monitoring of the physical activitycomprises: measuring the heart rate using a predetermined electrodeattached to the body when the physical activity is dynamic; measuringacceleration of physical movement of the body using an accelerometer;and outputting at least one of a physical activity pattern and caloriesexpended using the measured heart rate and the measured acceleration.19. The method of claim 16, wherein the adjusting and generating of theelectrical stimulation signal comprises: detecting an electromyographicsignal of the body; calculating a fatigue index indicating the degree ofmuscle fatigue by converting the detected electromyographic signal,detected during a predetermined time unit, into a frequency-domainelectromyographic signal; and adjusting the electrical stimulationsignal based on the calculated fatigue index and generating the adjustedelectrical stimulation signal.
 20. A medium comprising computer readablecode implementing the method of claim
 5. 21. A medium comprisingcomputer readable code implementing the method of claim
 16. 22. Anelectrical stimulation apparatus, comprising: an electromyogram detectordetecting electromyographic signals from a body; a fatigue indexcalculator calculating a fatigue index indicating a degree of musclefatigue, for at least a muscle in a body, by converting at least twodetected electromyographic signals into respective frequency-domainelectromyographic signals, with the calculated fatigue index being basedon a ratio with the at least two frequency-domain electromyographicsignals; and an electrical stimulation signal generator generating anelectrical stimulation signal, for application to the body, based on thecalculated fatigue index.
 23. The electrical stimulation apparatus ofclaim 22, further comprising: a heart rate measurer to measure a heartrate using a predetermined electrode attached to the body; and anactivity output unit to output at least one of a physical activitypattern and calories expended based on the measured heart rate.
 24. Theelectrical stimulation apparatus of claim 22, further comprising: anaccelerometer to measure an acceleration of physical movement of thebody; and an activity output unit to output at least one of a physicalactivity pattern and calories expended based on the measuredacceleration.
 25. The electrical stimulation apparatus of claim 24,wherein when the measured acceleration is greater than a predeterminedthreshold value the electrical stimulation signal generator does notgenerate the electrical stimulation signal.
 26. The electricalstimulation apparatus of claim 22, wherein the at least two detectedelectromyographic signals are detected at least at an initial point in apredetermined period and a final point in the predetermined period,respectively.
 27. The electrical stimulation apparatus of claim 26,wherein the initial point occurs when the electrical stimulationapparatus is applied to operate on the body.
 28. The electricalstimulation apparatus of claim 26, wherein the final point occurs whenthe electrical stimulation apparatus is removed from operating on thebody.